Questions tagged [generator]

A generator is a device that generates electricity from mechanical energy via different energy sources such as heat or kinetic energy of water.

111 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
3
votes
1answer
104 views

Generator voltage dipping at specific loads with observed increase in frequency

Background I have an interesting problem at hand on a diesel generator onboard a marine platform. The generator is rated at 380V, 50Hz, 3Ph and 1500kW output. Problem While conducting installation ...
3
votes
2answers
86 views

Wind-powered fairy lights + battery charger: preliminary help

I'm new here and asking for help designing a yard-art project. I would like to use a small DC motor as a wind-powered generator to charge a battery (with overcharge prevention) and run some battery ...
3
votes
0answers
146 views

Generator AVR Wiring Question

I'm replacing the AVR of a Honda EX4500s. However, the new AVR came with a 4-prong coupler plus two other wires (red and white), as opposed to the original 3-prong coupler (just like the 4-prong, but ...
3
votes
0answers
69 views

Bulk power markets hour ending convention why?

Is there an engineering explanation for the hour ending (HE) convention common to US Independent System Operators (ISO)? For example, hover over any MISO real time market data and they will show the ...
3
votes
2answers
145 views

Power system - Economic dispatch

Quick concept related question, I have a system with 5 generation units and I have to find the maximum demand that the system can support and still be N-1 secure. their max outputs are: Unit A= 155, ...
2
votes
1answer
69 views

Generator frequency control

We are trying to run an AC generator on an RV for a customer. On an RV as you drive the engine RPM goes up and down. As I understand it, that would change the outlut AC frequency. Is there an ...
2
votes
1answer
192 views

I found a motor/generator thing at my school's storage. I was wondering if anyone could identify it

Im not sure what this is because it has both a commutator and a stator. It didnt have anything else with it. Im guessing it has something to do with ac generation.
2
votes
0answers
117 views

High Frequency Pulse Rate Generator - Science Fair

( For our High School Science Fair) I am trying to find a pulse rate generator capable of producing 2.5Hz - 20,000 Hz utilize with over 10,000 LEDs all at once with several milliseconds in between ...
2
votes
0answers
469 views

Draw relation of rotation speed and output power of PMAC generator with brake resistor

I would like to draw a graph showing the relationship between rotation speed and power of an ideal Sinus PMAC generator with a brake resistor R(load) to be defined controlled via a 4Q Controller ...
1
vote
0answers
40 views

Output phase voltage of wye-connected synchronous generator

The question: The answer: However, theta is the angle difference between the terminal phase voltage and the line current as shown in Figure 20 below So, I think the answer would be 512/12 - 47/-34....
1
vote
0answers
47 views

Is it possible to regulate the amount of counter torque in a generator?

I have a question for a machine I am working on, The machine is used to pre-tension steel wire ropes for maritime uses, the wire rope sits on a drum with a 2m diameter. The tension has to be ...
1
vote
1answer
61 views

Bus Bar voltage calculations for renewable integration to grid

I am confused on the problem bellow I started off by use P=IV = V^2/Z --> V=sqrt(P*Z) Assume at each bus bar the power from the PV is being given to the grid with +6KW from knowning that the PV ...
1
vote
0answers
91 views

Calculating the line-to-neutral voltage of a generator

A three-phase generator is connected to a strong grid with line-to-line voltage 14 kV and frequency 50 Hz. The generator is rated at 15 kV and 180 kVA. The resistance in the windings is 2 Ohm/phase ...
1
vote
0answers
42 views

How to measure the current generated in permanent magnet dc motor/generaator?

A motor of dia 1cm and 3 cm height and 200gms of weight. will it be able to generate 6 amperes of current? Can it handle that much amount of current? If not then how can I measure the current ...
1
vote
2answers
66 views

How can you predict the power an electrical generator (alternator) produces?

We have to design an electrical alternator in a multiphysics software, but we can't seem to figure out how to deduce the power it will produce. We need to charge a capacitor to 1000 joules (at 2000V) ...
1
vote
0answers
74 views

How can I efficiently convert the output voltage of a 3 phase generator of 700V to 12V, 24V or 48V DC?

I recently bought a wind turbine electric brushless generator rated for 3kW. I noticed that the output voltage is really high - it is around 700V at 5400 RPM. After some research on stackexchange, I ...
1
vote
0answers
24 views

In a non-magnet, excited-coil generator, what percentage of the generator's total output is used to excite the coil?

I am building a DC permanent-magnet generator with the magnets in the rotor. The stator coils are my unique winding. The overall efficiency of the generator is measured with a digital torque meter ...
1
vote
0answers
63 views

Voltage/Frequency characteristics as a motor dies off

So, hopefully this is a simple enough answer for someone. I was recently posed a question concerning the coastdown characteristics of a pump as they pertain to the trip setpoints of a breaker. One ...
1
vote
0answers
60 views

Transmission Bus Admittance Question

I have a question about calculating the admittance between buses in the single line diagram shown below: The solution I have been given shows that the admittance between bus 2-2 is found by adding ...
1
vote
0answers
50 views

Does transformer line side voltage varies with backup generator on load side running at from 0 to 100%?

We have a transformer of 750 KVA with 5.75% impedance. On the load side we have loads and a back-up emergency generator. This emergency generator is capable of supplying the loads and still export ...
1
vote
1answer
50 views

Is there a RF signal device for a 120 or 240 vac wire to start and stop a standby generator?

Our standby generators automatically start when a switch in the automatic transfer switch closes and the gen stops when that switch opens. Usually we bury 2 16ga wires along with two 120/240v hot and ...
1
vote
0answers
77 views

Ripple on tens-millivolts sinus waveform

I’m trying to make a DDS to generate a sinusoidal signal with tens to hundreds of millivolt amplitude and hundreds kHz frequency using an LTC1666 DAC. But I have some confusing results. Device ...
1
vote
2answers
245 views

Why does rotor of synchoronous generator accelerate during faults?

I don't understand the electrical torque in a generator. Isn't the counter torque related to the armature current in the generator? Why does electrical torque decrease during fault in lines that ...
1
vote
1answer
29 views

What is the reason for compensation at async generator outputs?

I see capacitor banks are installed at async generator outputs. What is the function of compensation in this case? I thought compensation was done at the consumer and for induction motors. Can this ...
1
vote
0answers
61 views

Generate energy from waves that move my ship?

I'm currently building a small solar powered robot boat. I expect it to work fine (because why not.. :-) ), but I'm already looking for other ways than only solar panels to generate electrical power. ...
1
vote
0answers
58 views

connecting 3 one phase Generator to get three phases

I have a big welder machine that needs around 26 kW and three phases. A generator for this power is a little bit expensive and take me a while to import one. When you are in a complicated situation ...
1
vote
0answers
93 views

Hook up an automatic transfer switch with two phases only

We have a house in Haiti connected to the shore line. The shore line isn't always working so we bought a generator. I wanted to ground one of the two phases to create one neutral, one phase and a ...
1
vote
1answer
60 views

How to optimze a coil for needed voltage?

Faraday's law for a coil is : V = A * M * N Where: V = Peak output-voltage A = Area of the cross-section of the wire M = Rate of change of magnetic flux in the coil N = Number of turns of the ...
1
vote
0answers
120 views

Charging 3.7V battery from 300W+ generator

I am doing a project involving a bike generator of 500W. All of my previous projects were small LiPo battery powered devices so I want to double check certain aspects of this relatively high power ...
1
vote
0answers
191 views

Is this stackable low RPM generator design viable?

I'm trying to invent viable hand-crank energy generator for charging phones and similar low-power appliances. I want to avoid gears altogether in the design, because they are hard to manufacture at ...
1
vote
1answer
188 views

Generated current in a \$3\times450\$ VAC \$60\$ Hz \$1150\$ kVA generator

Let's say I've a \$3\times450\$ VAC \$60\$ Hz \$1150\$ kVA generator. How much current will there be generated when it runs at maximum capacity? MY WORK: The total Active power over a three-fase ...
1
vote
0answers
83 views

Change in frequency in a grid that has lost generation?

I have an example about droop and it asks to calculate final frequency in a grid after one generator power generation is lost. The answer is given as 59.889 Hz; however, I am calculating as 59.99 Hz. ...
1
vote
0answers
912 views

What might cause a fluctuating resistance of a generator winding?

Before assembly of a machine that contains a three phase generator I check the resistance between the 3 phases of the generator with an ohmmeter. The generator is kept stationary and the temperature ...
1
vote
0answers
129 views

Programmable GHz signals

I would like to generate custom waves in the gigahertz range. With beginner FPGAs like the DE0-Nano or microcontrollers like the Arduino, I can only generate waves up to the kilohertz range. What ...
1
vote
0answers
96 views

Why would venting an engine create a negative amperage on a generator?

I'm writing simulation software for a civilian helicopter. The helicopter has two engines and two generators. Normally, we calculate the amperage reading of a generator through Ohms. I = W / V. ...
1
vote
0answers
52 views

Does an HEV Genset need a controller?

I am part of a team at school that designs and builds a hybrid electric vehicle. We have chosen to use a series hybrid configuration, so we will be using a motor as a generator to charge lithium ...
1
vote
0answers
283 views

BLDC Motor and Generator, query about capacitor bank

I have 3 phase generator (believe to be Wye) which goes to 6 diode rectifier, the rpm can goes from 1000 to 5000. The output of the rectifer (50V say) has ripple on top which goes to 100W Motor ...
1
vote
0answers
404 views

Stepper motor as generator

The answer to "DC Motor as a Generator Voltage and Current" from Olin Lathrop included: "Sometimes these parameters can be inferred from other specs. For example, consider a motor that ...
1
vote
0answers
656 views

Bottle dynamo (bike generator) rectification and stabilization circuit for LED light

A friend of mine would like to convert her bottle dynamo (bike generator) to run a LED light. The light needs to stay on for maybe 90 secs when the bike is stopped, and needs to blink (using a ...
1
vote
0answers
221 views

How much has the power density of electrical motors and generators changed in recent decades?

I would like to know how much lighter (if at all) a matched combination of an electrical motor and generator with a given power output would be today, compared to a similarly powerful combination ...
0
votes
0answers
21 views

Internal EMF of a Synchronous Generator Relationship with Load side line Voltage

Say you have a 6-pole, star-connected, 60 Hz, 25 MVA rated, 600 V synchronous generator. After conducting open and short circuit tests you get the equivalent circuit with Xs = 600/(root(3)*14000) (...
0
votes
0answers
51 views

Standard equation for delivered power from synchronous generator wrong for fractional kW machines?

When synchronous machines get to a certain size (in the \$MW\hspace{-0.8mm}s\$) the armature resistance is a lot smaller than the synchronous reactance, \$R_A << X_s\$, because of this \$R_A\$ ...
0
votes
1answer
40 views

Smart Power Restore Alarm

I have a portable generator I am going to use with an interlock system, which prevents back current to the grid, to power the house during outages. Knowing I would need a power return alarm to notify ...
0
votes
0answers
27 views

Why does the short circuit current increase when we connect a distributed generator?

I read that the short circuit current increases when we connect a generator to the grid. Why? Is this true for any kind of generator? (PV, wind turbine, synchronous generators, etc.)
0
votes
0answers
42 views

Motor/Generator Set Using Car Alternator

So I've recently been learning that car alternators are just three phase synchronous motors with external DC field excitation. To access the three phases it may be necessary to take them apart, ...
0
votes
1answer
30 views

Charging a 5v battery bank with 4.2 volt battery

So I wanted to make a hand-cranked battery charger for my power bank, and I figured that if I connect a generator to a lithium battery I had lying around, I could use the output of that lithium ...
0
votes
0answers
40 views

Generator AVR - blue / yellow wire pairs

I'm replacing the automatic voltage regulator (AVR) on a Suntom 6500T generator (apparently identical to the more common Kipor KDE6500T and other generic Chinese 5.5kW generators). The original AVR ...
0
votes
0answers
48 views

Is it viable to short pitch different windings by different degrees of short pitching in the same synchronous generator?

In the design of a synchronous generator one can chose to eliminate or reduce harmonics at the expense of emf. The pitch factor \$K_p = \cos(\alpha/2)\$, which is always less than or equal to 1, ...
0
votes
0answers
39 views

Synchronous generator governor

The way I understand the governor of a synchronous generator is as follows: As loads change on the system, the frequency will change. The governor's purpose is to maintain an approximately constant ...
0
votes
0answers
31 views

Generator internal voltage calculation

The question: The answer: However, I think the answer is wrong, it should be: Vi = Vt + IdXd = 1+ 0.971.1j = 1.46 pu So, the voltage is 1.46 * 250 kV = 365.6 kV Do you agree?